Drug infusion systems can dispense fluid medication, containing a drug, to a patient. Some drug infusion systems are portable, allowing a patient to receive fluid medication while remaining mobile. In addition, some drug infusion systems are implantable to more effectively and less obtrusively dispense such fluid medication to a patient.
Devices and techniques for treating a patient by drug infusion, and/or by electrical stimulation of a person's central nervous system, are well known in the prior art. For instance, U.S. Pat. No. 5,782,798, Rise, entitled Techniques For Treating Eating Disorders By Brain Stimulation and Drug Infusion; U.S. Pat. No. 5,814,014, Elsberry et al, Techniques of Treating Neurodegnerative Disorders by Brain Infusion, each assigned to Medtronic, Inc., Minneapolis, Minn., disclose such devices and techniques are hereby incorporated by reference.
Another example of a drug infusion device is shown in U.S. Pat. No. 3,527,220, Summers, entitled Implantable Drug Administrator, an implantable drug administrator having a refillable bladder which can be filled with a drug and a pump for selectively pumping the drug from the bladder into any desired area of the body. The administrator includes an indicator for indicating when the desired amount of the drug has been injected.
In U.S. Pat. No. 3,951,147, Tucker et al, entitled Implantable Infusate Pump, a rechargeable infusate pump for implantation in the human body can be refilled periodically by injection through an inlet septum under the skin. A conduit conducts fluid to an infusion site in the body. The pump outlet includes a special controller flow controller which is able to very accurately meter the infusate to the selected body site.
A problem with these implantable drug infusion devices is that there is no way to provide a simple external means to select the dosage amounts and intervals from a wide range of possible doses and intervals, and verify that a desired change had been made.
U.S. Pat. No. 4,146,029, Ellinwood, Self-Powered Implanted Programmable Medication System and Method, discloses a device and method for dispensing medication internally of the body utilizing an implanted system which includes medication storage and dispensing control circuitry having control components which may be modified by means external of the body being treated to control the manner of dispensing the medication within such body. In particular, extracorporeal control means may provide some measure to achieve selected medication programs corresponding to particular codes.
U.S. Pat. No. 4,692,147, Duggan, Drug Administration Device, assigned to Medtronic, Inc., Minneapolis, Minn., discloses an implantable drug administration device which can be non-invasively programmed to change both the dosage amount and the dosage interval. Verification of the received dosage and interval commands is achieved by means of an audio transducer which is attached to the device case.
The implantable drug administration device described in Duggan allows a medical professional to program to the delivery rate of a drug contained in the reservoir of the device over a specified interval. The process, however, to achieve an even reasonably complex dosing regimen is laborious and time consuming. Each interval must be specified and the particular delivery rate must be individually programmed. For all but the simplest of dosing regimens, this system is not only laborious and takes too long to program but also prone to error due to the painstaking programming steps which must be accomplished.